"We're cautious with players when they're not fit and full-speed ready to go," Smith said more than a week ago, via the Chicago Sun-Times. "But once we get them out there, we're never trying to take out any of our players in practice."

That quote above is one reason why Bears fans should be concerned. Urlacher has missed four straight days of practice with a knee injury. He won't play in the team's preseason opener. He could miss most of the preseason.

Urlacher is coming off a resurgent season and remains so valuable to the Bears because they have no one behind him. Nick Roach would likely take over at middle linebacker. Former Tampa Bay Buccaneer Geno Hayes would probably start, too.

At this point, Urlacher has no desire to undergo further surgery on his knee. This could be a problem that doesn't go away.